visualizeAovTask.h

//
// Copyright 2021 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef HDX_VISUALIZE_AOV_TASK_H
#define HDX_VISUALIZE_AOV_TASK_H
 
#include "pxr/pxr.h"
#include "pxr/base/gf/vec3i.h"
#include "pxr/imaging/hdx/api.h"
#include "pxr/imaging/hdx/task.h"
#include "pxr/imaging/hdx/tokens.h"
#include "pxr/imaging/hgi/attachmentDesc.h"
#include "pxr/imaging/hgi/buffer.h"
#include "pxr/imaging/hgi/graphicsPipeline.h"
#include "pxr/imaging/hgi/resourceBindings.h"
#include "pxr/imaging/hgi/shaderProgram.h"
#include "pxr/imaging/hgi/texture.h"
#include "pxr/usd/sdf/path.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
struct HdxVisualizeAovTaskParams;
 
class HdxVisualizeAovTask : public HdxTask
{
public:
    using TaskParams = HdxVisualizeAovTaskParams;
 
    HDX_API
    HdxVisualizeAovTask(HdSceneDelegate* delegate, SdfPath const& id);
 
    HDX_API
    ~HdxVisualizeAovTask() override;
 
    HDX_API
    void Prepare(HdTaskContext* ctx,
                 HdRenderIndex* renderIndex) override;
 
    HDX_API
    void Execute(HdTaskContext* ctx) override;
 
protected:
    HDX_API
    void _Sync(HdSceneDelegate* delegate,
               HdTaskContext* ctx,
               HdDirtyBits* dirtyBits) override;
 
private:
    // Enumeration of visualization kernels
    enum VizKernel {
        VizKernelDepth = 0,
        VizKernelId,
        VizKernelNormal,
        VizKernelFallback,
        VizKernelNone
    };
 
    HdxVisualizeAovTask() = delete;
    HdxVisualizeAovTask(const HdxVisualizeAovTask &) = delete;
    HdxVisualizeAovTask &operator =(const HdxVisualizeAovTask &) = delete;
 
    // Returns true if the enum member was updated, indicating that the kernel
    // to be used has changed.
    bool _UpdateVizKernel(TfToken const &aovName);
 
    // Returns a token used in sampling the texture based on the kernel used.
    TfToken const& _GetTextureIdentifierForShader() const;
 
    // Returns the fragment shader mixin based on the kernel used.
    TfToken const& _GetFragmentMixin() const;
 
    // ------------- Hgi resource creation/deletion utilities ------------------
    // Utility function to create the GL program for color correction
    bool _CreateShaderResources(HgiTextureDesc const& inputAovTextureDesc);
 
    // Utility function to create buffer resources.
    bool _CreateBufferResources();
 
    // Utility to create resource bindings
    bool _CreateResourceBindings(HgiTextureHandle const& inputAovTexture);
 
    // Utility to create a pipeline
    bool _CreatePipeline(HgiTextureDesc const& outputTextureDesc);
 
    // Utility to create a texture sampler
    bool _CreateSampler(HgiTextureDesc const& inputAovTextureDesc);
 
    // Create texture to write the colorized results into.
    bool _CreateOutputTexture(GfVec3i const &dimensions);
 
    // Destroy shader program and the shader functions it holds.
    void _DestroyShaderProgram();
 
    // Print shader compile errors.
    void _PrintCompileErrors();
    // -------------------------------------------------------------------------
    
    // Readback the depth AOV on the CPU to update min, max values.
    void _UpdateMinMaxDepth(HgiTextureHandle const &inputAovTexture);
 
    // Execute the appropriate kernel and update the task context 'color' entry.
    void _ApplyVisualizationKernel(HgiTextureHandle const& outputTexture);
 
    // Kernel dependent resources
    HgiTextureHandle _outputTexture;
    GfVec3i _outputTextureDimensions;
    HgiAttachmentDesc _outputAttachmentDesc;
    HgiShaderProgramHandle _shaderProgram;
    HgiResourceBindingsHandle _resourceBindings;
    HgiGraphicsPipelineHandle _pipeline;
 
    // Kernel independent resources
    HgiBufferHandle _indexBuffer;
    HgiBufferHandle _vertexBuffer;
    HgiSamplerHandle _sampler;
 
    float _screenSize[2];
    float _minMaxDepth[2];
    VizKernel _vizKernel;
};
 
 
struct HdxVisualizeAovTaskParams
{
    HDX_API
    HdxVisualizeAovTaskParams();
 
    TfToken aovName;
};
 
// VtValue requirements
HDX_API
std::ostream& operator<<(std::ostream& out, const HdxVisualizeAovTaskParams& pv);
HDX_API
bool operator==(const HdxVisualizeAovTaskParams& lhs,
                const HdxVisualizeAovTaskParams& rhs);
HDX_API
bool operator!=(const HdxVisualizeAovTaskParams& lhs,
                const HdxVisualizeAovTaskParams& rhs);
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif